Goal is to create a 64 MJ cannon capable of firing ten high impact metal slugs per minute

The U.S. Navy is anticipating the railgun will play a key role in battlefields of the future. To that end it's investing deeply in the technology, gunning to make the U.S. the first to deploy the wild weapons technology. The U.S. Navy and its research wing -- the Office of Naval Research (ONR) -- announced this week that in 2016 the railgun efforts will see a crucial test: the first live fire demonstration at sea.

I. A Brief History of Railguns

France’s Louis Octave Fauchon-Villeplee first proposed the concept of an “electric gun” in 1918, later getting a patent on the technology in the U.S. in 1922. Railguns have long been speculated to potentially have critical advantages over traditional guns. Like missiles and other propellant based high-speed projectiles, they can achieve much higher velocities that traditional projectiles which lack internal propulsion. However, railguns are expected to be much cheaper than rockets, given that their ammo can be crude metal slugs.

Railguns operate by utilizing the Lorentz force or "Lorenz (sic) force" as the U.S. Navy refers to it as in a press release. This phenomenon involves the application of force from electromagnetism on point charge.

The simplest form of the railgun -- the one the U.S. Navy will likely look to first deploy -- involves a sliding metallic conductor that acts as a homopolar motor in the cannon, accelerating down a pair of magnetized rails of opposite charges. The armature can be integrated into the projectile itself, but typically it is attached to the rails so that nonmagnetized projectiles can be fired from the cannon.

More exotic variants use electrical arcs across ionizing gas to create a propellant effect similar to a traditional chemical (e.g. firepowder) based cannon.

Given the benefits, military designers worldwide have long been chasing after railguns. In World War II, the Nazis hatched designs to build anti-aircraft railguns. Recent analyses suggest these plans may have been technically feasible, however, they would have used as much power as half the city of Chicago, making them somewhat farfetched. They were never built.

II. Railguns Approach the Battlefield

With the advent of high-energy solid-state switches and high-energy-density capacitors, at last the power necessary to rapidly magnetize the rails and eject the projectile has been at least made a practical reality.

The U.S. Navy has been kicking around prototypes for some time. Its plan is to deploy a 64 Megajoule cannon to warships sometime around 2020-2025. That device will use tungsten slugs and will fire at speeds of around 5,800 m/s (19,000 ft/s or roughly 13,000 miles per hour). At that rate the cannon will be able to accurately to hit a 5-meter (16 ft) target from roughly 200 nmi (370 km) away. The goal is to be able to fire 10 shots per minute.

The tungsten slugs are expected to have enough kinetic force to punch through even the best tank armor of today. Line of site is a problem with railguns, but the advent of drone sighting technology -- a key area of research at the U.S. Navy -- will likely nullify this disadvantage by the time the tech hits the high seas.

The JHSV is the Navy's next generation troop ship. Currently, 10 are either built or under construction and another 13 will be added by the year 2041.

The JHSV is technically a non-combatant, however, it was selected for this test due to its flexibility and roomy deck.

BAE's prototype railgun [Image Source: U.S. Navy]

One of the biggest challenges facing railgun designers is to shrink the cannons down to the size of traditional naval artillery. Currently a team at UK-based BAE Systems plc (LON:BA) and the Electromagnetic Systems (EMS) Division at privately-owned U.S. defense contractor General Atomics, have both delivered the Navy competing prototype designs.

The electromagnetic railgun represents an incredible new offensive capability for the U.S. Navy. This capability will allow us to effectively counter a wide-range of threats at a relatively low cost, while keeping our ships and sailors safer by removing the need to carry as many high-explosive weapons.

Rear Adm. Matt Klunder, the chief of naval research, adds:

Energetic weapons, such as EM railguns, are the future of naval combat. The U.S. Navy is at the forefront of this game-changing technology.

quote: So for decades the navy big gun ships are being decommisoned as big cannons are >typically< not needed in modern war.

I agree. It's too bad the USA no longer has any active 16" battleships. They're all museums now. Not only do battleships have foot thick steel, compared to the USS Cole, they also have plenty of room for multiple rail guns. If the USA had money, we could redesign our battleships with modern labor saving devices. Then they could have a smaller crew and be cheaper to run.

The problem is, the USA is broke. That is, our large USA corporations have not been paying any taxes so the country is broke. You're not going to hear about this on any of the cable news channels because they are... sponsors!!! You should know, because the USA no longer has enough money, they're shrinking the size of the Army to pre-WW2 levels and eliminating the A-10 Warthog.

There are several documentaries you must see:1. Inside Job , not available via Netflix Streaming, only DVD.2. We're Not Broke 3. Park Avenue: Money, Power and the American Dream 4. Gasland I & II 5. Split Estate